Cancer biology: Integumental epithelium from normal skin, benign cutaneous hyperplastic lesions, precancerous lesions and cancerous lesions are grown in culture, and conditions for their survival, proliferation and differentiation are determined. Epithelium from skin treated with chemotherapeutic agents is similarly grown and similarly tested. Carcinogenesis: Attention is directed to the effects of cancer chemotherapeutic agents on skin, and whether certain drugs are significantly carcinogenic. Tissues exposed to such drugs are monitored clinically, histopathologically, and by growth characteristics in culture. The effects of certain drug-chemicals, in titrated doses, on proliferation and differentiation of cells in culture are determined. Cancer therapy: While early stage integumental epithelial cancer as well as cutaneous lymphomas have now been shown to be curable by early administered topical therapy, later stage disease is less responsive. The role of inflammation, immunologic and non-immunologic, on the development and control of such neoplastic lesions is explored by clinical investigative procedures applied to skin of patients having such diseases.